• 전기의세계
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• v.13 no.2
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• pp.20-22
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• 1964

일찌기 1930년대에 미국에서 냉간압정법에 의한 방향성규소강대의 제조에 성공한 이래 이의 자기적특성에도 비약적인 향상을 가져와 미국에서 이미 이를 사용한 권철심형변압기가 실용화되고 있는지 오래거니와, 가까운 일본만 하여도 1958년에 권철심형주상변압기가 제조 완성되었으며, 현재는 주상변압기의 대부분이 종래의 적철심형변압기와 교체되고 있는 실정이다. 더우기 최근에는 소형의 주상변압기 뿐만아니라 중형의 권철심형 배전용변압기 제작도 가능하게 되어 그야말로 배전용 변압기분야엔 권철심형변압기 전성시대가 온것이다. 이처럼 권철심형변압기가 크게 환영받는 이유는 방향성 규소강대의 우수한 자기적인 특성을 이용하여 고성능인 동시에 소형, 경량으로 만들었다는 점이다. 국내 제조업계에서도 이와같은 세력의 영향을 받아 각 사회가 경쟁적으로 개발에 착수하고 있거니와, 거년에 일사회에서 50kVA이하 각 용량의 주상변압기 생산을 개시하게 되어 전업계에서 점차로 권철심형변압기에 관심을 모으게 되어으므로 이하에 권철심형변압기의 특성과 제조과정에 대하여 간단히 기술하고저 한다.

• 주택과사람들
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• s.206
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• pp.64-67
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• 2007

최근 아파트의 층수가 더욱 높아지고 있다. 주상복합 아파트의 장점인 첨단 보안 시스템과 다양한 커뮤니티 시설, 고급 마감재 등을 적용하는 데 그치지 않고 30층 이상의 고층 아파트로 지어지고 있다. 주상복합 아파트의 장점은 적용하고, 단점은 배제한 초고층 아파트의 건축 트렌드에 대해 알아본다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.1
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• pp.102-108
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• 2000

This paper presents a result of practical study about the adjustment of load correlation equation for the load management of pole transformer. For adjusting the load correlation equation, we analyze the correlative relation between working electric energy[kWh] and peak load[A]. To enhance the accuracy of correlation equation, we classify the 12 representative area patterns. And then, we select the 24 sample pole transformer for each area pattern. For the reliability of the data using the load correlation equation, load management equipment is utilized for each sample pole transformer. Through the on-line data acquisition, we construct the database. For adjusting the load correlation equation, we consider the two points. One is the goodness of fitness for load correlation equation and the other is prevention of pole transformer damage due to the overload. Finally, we propose the correlation equation using the linear and quadratic equation all at once. Through the case studies, we verify that the proposed load correlation equation is reduced the error ratio than conventional correlation equation.

• Korean Journal of Construction Engineering and Management
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• v.7 no.2 s.30
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• pp.62-70
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• 2006

As buildings are changing variously from the side of use, efficiency and size, the construction qualities are more importantly recognized. Supervision system was enacted in the Residential Building Law in 1990 and responsibility supervision system in the Construction Engineering Management Law in 1994, respectively. However, recently revised supervision system in 2003 has some limitations: the present problems of appointing supervisor, disposing the supervisors, supervisor's works. Therefore, the aim of this study is to improve the present supervision system for mix-use residential building. By implementing the proposed revised supervision system, it will be able to expect quality improvement, confidence of the owner and the user, development of construction technology, and increase international competitiveness of supervision company.

• Journal of the Korean GEO-environmental Society
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• v.16 no.5
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• pp.5-11
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• 2015

The double sheeted permeable reactive barrier containing two different reactive materials can be applied to remediate the groundwater contaminated by nutrients and heavy metals. In this study, in order to evaluate the removal efficiency of contaminants including ammonium, cadmium and phosphate by double layered permeable reactive barrier containing zeolite and steelmaking slag, column tests were performed. In addition, nonequilibrium reaction in column tests was analyzed by two-site nonequilibrium advection-dispersion model. Column test results showed that zeolite is effective for removal of ammonium, while steelmaking slag is effective for removal of phosphate and cadmium. The sequential reaction of zeolite and steelmaking slag gave the better removal efficiency for ammonium.

• Land and Housing Review
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• v.4 no.3
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• pp.295-301
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• 2013

In this study, cases of domestic tall residential buildings were investigated for the structural types, numbers of stories, total heights, type of lateral load resisting systems, and zoning of concrete strength. Based on these investigation data, the structural planning pattern of tall residential building was analyzed. SRC structure is main structural types of tall residential building at the initial stage of domestic tall residential building, but RC structure is substituted for main structural types since 2005. Retaining wall system is positioned at the core part of structural plan as a lateral load resisting system. Concrete strength zoning of vertical members like columns are divided by vertical heights of lower parts, middle parts, and upper parts. Basic data of structural planning of 40stories and 60 stories residential buildings was proposed based on case investigation.

• Economic and Environmental Geology
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• v.48 no.6
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• pp.509-523
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• 2015

This study introduces newly implemented geological well logs database for Jeju public water wells, built for a research project focusing on integrated hydrogeology database of Jeju Island. A detailed analysis of the existing 1,200 Jeju Island geological logs for the public wells developed since 1970 revealed six major indications to be improved for their use in Jeju geological logs DB construction: (1) lack of uniformity in rock name classification, (2) poor definitions of pyroclastic deposits and sand and gravel layers, (3) lack of well borehole aquifer information, (4) lack of information on well screen installation in many water wells, (5) differences by person in geological logging descriptions. A new Jeju geological logs DB enabling standardized input and output formats has been implemented to overcome the above indications by reestablishing the names of Jeju volcanic and sedimentary rocks and utilizing a commercial, database-based input structured, geological log program. The newly designed database structure in geological log program enables users to store a large number of geology, well drilling, and test data at the standardized DB input structure. Also, well borehole groundwater and aquifer test data can be easily added without modifying the existing database structure. Thus, the newly implemented geological logs DB could be a standardized DB for a large number of Jeju existing public wells and new wells to be developed in the future at Jeju Island. Also, the new geological logs DB will be a basis for ongoing project 'Developing GIS-based integrated interpretation system for Jeju Island hydrogeology'.

• The Journal of the Petrological Society of Korea
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• v.22 no.1
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• pp.9-17
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• 2013

Trachytic cliff showing a unique appearance like noodle is located in the Mt. Bipa, Seo-myeon, Ulleung island. This cliff is named 'Guksubawi'(means noodle-like rock) by its appearance. There is cliffs on three sides except north side and each side shows semi-vertical columnar joints obviously. This columnar joint has different character in appearance and mineralogy according to their direction and this tendency is remarkable in contrast between the east side and the west side. The consideration of the cooling processes after eruption of trachytic lava based on the contrast of both columnar joints dealt in the full text. In the morphological approach, the columnar joint on the east side has narrower space and chisel-like marks than the west side. And the joint walls are sharper on the east side than west side too. In the mineralogical approach, then, trachyte on the west side has bigger phenocrysts than the east side and is showing glomeroporphyritic texture and weak trachytic textures of lath of plagioclase. Around these differences between the east side and the west side, it modelled the typical temperature gradient while the cooling processes of hot rocks and the east side, consequently, corresponds to exterior of the entire trachytic volume. The columnar joint of the Guksubawi has the value of landscape and scientific importance about the forming processes of the columnar joint of trachytic lava, and so supposed it has enough values to preserved as natural heritage.

• Journal of Conservation Science
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• v.37 no.5
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• pp.505-515
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• 2021

In this study, we evaluated the slope stability of the Pohang Daljeon-ri columnar joint (Natural Monuments # 415) and calculated the maximum energy, jumping height and moving distance of rockfalls using a simulation. Based on the results, we established the range of rockfall risk. The slopes of the Pohang Daljeon-ri columnar joint have dip directions of 93.79°, 131.99°, 165.54° and 259.84° from left (SW) to right (NE). Furthermore, they have a fan-like shape. The Pohang Daljeon-ri columnar joints are divided into four sections depending on the dip direction. The measurement results of the discontinuous face show that zone 1 is 125, zone 2 is 261, zone 3 is 262, zone 4 is 43. The results of slope stability analyses for each section using a stereographic projection method correspond to the range of planar and toppling failure. Although it is difficult to diagnose the type of failure, risk evaluation of currently falling rocks requires further focus. The maximum movement distance of a rockfall in the simulation was approximately 66 m and the rockfall risk range was the entire area under slope. In addition, it is difficult to forecast where a rock will fall as it rolls in various directions due to topographic factors. Thus, the installation of measures to prevent falling is suggested to secure the stability based on the results of the rockfall simulations and its probabilistic analysis.

• Journal of the Korean earth science society
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• v.39 no.6
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• pp.575-592
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• 2018

This study investigates the formation mechanism of columnar joints at the Sanin Kaigan Geopark in Japan based on its morphology, rock type and igneous structure. Columnar joints distribute to five areas of three prefectures. That is, Kyogasaki, Byobuiwa, Tateiwa and Kyugenkado in Kyotango area of Kyoto prefecture; Genbudo and Kinumaki Shrine in Toyooka City of Hyogo prefecture; Yoroinosode, Takanosushima, Mini-Yoroinosode in Kamicho Town of Hyogo prefecture; Miooshima and Nagasakihana, Shitaara Domon, Kuzakuishi, Moroyose dyke in Shinonsencho Town of Hyogo prefecture; Shirawara dyke in Iwamicho Town in Tottori prefecture. Igneous structures are divided into three types: lava flow, sill and dyke. Lithologies are divided into five types including basalt, andesite, dacite, rhyolite, and quartz porphyry. Lava flow shows colonnade and entablature. However, entablature is not seen in the sills and dykes in the area. Although the polygons of columnar joint vary from tetragon to octagon, hexagon is most frequently found. The width of colonnades ranges from 10cm to 1m, but their size does not correlate with its $SiO_2$ contents. Meanwhile, their size and morphology at single site are comparatively uniform.